Surgical procedures requiring cutting of tissue can cause bleeding at the site of the cutting. Various techniques have been adapted to control bleeding with varying degrees of success such as, for example, suturing, applying clips to blood vessels, and stapling, as well as electrocautery and other tissue heating techniques. Advances in tissue joining or welding, tissue repair and wound closure also have permitted surgical procedures previously not possible or too risky.
Surgical staplers have been used for tissue security, joining, and approximation, and to provide hemostasis in conjunction with tissue cutting. Such devices include, for example, linear and circular cutting and stapling instruments. Typically, a linear cutter has parallel rows of staples with a slot for a cutting means to travel between the rows of staples. This type of surgical stapler secures tissue for improved cutting, joins layers of tissue, and provides hemostasis by applying parallel rows of staples to layers of surrounding tissue as the cutting means cuts between the parallel rows. In these devices, lockout mechanisms have been described to prevent refiring of single-shot staple cartridges.
Electrosurgical devices have been used for effecting improved hemostasis by heating tissue and blood vessels to cause coagulation or cauterization. U.S. Pat. No. 5,403,312 discloses a clamping and cutting device that clamps tissue, applies electrosurgical energy to the tissue and cuts the tissue. A described preferred embodiment also applies staples to tissue held by the device. Other instruments have been used for cutting and coagulating tissue, using other tissue heating energies, such as, for example, ultrasound, laser, thermal and infrared light.
It is desirable to provide a means for controlling a hemostatic tissue heating device with cutting and/or stapling functions, to prevent an improper sequential application of these functions. For example, to prevent cutting before providing hemostasis. It is also desirable to provide a means for preventing instrument use when the staple cartridge is empty, before tissue heating energy has been applied, or when tissue treatment is incomplete.